JP2004233160A - Contamination inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contamination inspection device that can accurately find the degree of radioactive contamination of an object to be measured even when the degree is converted into a surface contamination density, by obtaining a more detailed distribution than the width of a detector without lowering the sensitivity of a radiation detecting means. <P>SOLUTION: This contamination inspection device is provided with the radiation detecting means 1; a radiation counting means 2 constituted of an amplifier, a counter, a computer or multi-channel scaler which reads out and stores counted values, etc.; and a discrete value integrating means 3. This device is also provided with an activity and contamination density converting means 4, a contamination distribution displaying means 5, and a transporting speed and counting time control means 6 which sets and controls the transporting speed of the object to be measured and counting time intervals. In addition, this device is also provided with an object-to-be-measured transporting means 7. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

ここで、Ｒ１１からＲ７６までは放射線検出手段１の応答関数、Ｄ１からＤ６までは放射線分布、Ｍ１からＭ７までは放射線計数手段２で得られた計数結果である。
【００７０】
上式により、汚染分布Ｄ１からＤ６までの値は、計数結果Ｍ１からＭ７までの値に、応答関数Ｒ１１からＲ７６までの逆関数を掛けることで得られる。
【００７１】
たとえば、求める放射線分布の位置が検出器の前面に来た場合の検出器の応答を１とし、前面ではないときの検出器の応答を０とした場合、以下のような応答関数となる。
【００７２】
【数２】

なお、Ｍ１からＭ７については、計数積分結果で得られたＡ１からＡ６としても良い。
【００７３】
本実施形態によれば、予め求めておいた放射線検出手段に対する放射線検出感度の応答関数の逆関数を測定データに掛け放射線分布情報を求めるので、検出器の大きさより細かい分布を求めることができ、精度良く汚染分布を測定することが可能である。
【００７４】
第６実施形態（図６）
図６は、本発明の第６実施形態を示す構成図である。
【００７５】
図６に示すように、本実施形態では、任意の統計精度となるような計数値を閾値として記憶しておく判定閾値記憶手段９ｇを備えている。また、計数積算手段３から入力される計数値と閾値を比較して、閾値以下であれば分布補正をしないと判定する分布精度判定手段１０ｂとを備えている。また、判定の結果、分布補正しない場合の処理を行うとともに、分布補正を行うと判定した場合に放射線分布を求め補正する処理を行う分布補正手段１１を備えている。他の構成については前記実施形態とほぼ同様である。
【００７６】
このような構成において、検査時には、放射線検出手段１、放射線計数手段２、計数積算手段３により求められた計数値は、分布精度判定手段１０ｂにより、前もって判定閾値記憶手段９ｇに記憶されている閾値と比較される。そして、計数値が閾値より低い場合には分布精度が得られず、分布補正を行わないと判定される。また、計数値が閾値より高い場合には、分布精度を高めるため放射線分布を求め補正すると判定される。
【００７７】
分布補正を行わないと判定された場合には、分布補正手段１１において、例えば放射能量を所定の面積で除算して表面汚染密度を算出するような、安全側に評価される換算処理が一律に行われる。また、一律に均一汚染と仮定して補正が行われる場合もある。分布補正を行うと判定された場合には、分布補正手段１１において、求められた計数から分布情報を求めて補正処理が行われる。
【００７８】
本実施形態ではこのように、予め設定された統計誤差となる計数値を閾値として記憶し、放射線計数値と閾値を比較して閾値より低い場合には、計数精度が悪いので放射線分布は求めず一律の換算処理を行い、閾値以上なら測定結果から放射線分布を求める。これにより、放射線計数値が小さく十分な統計精度が得られない場合においても、十分に信頼性の高い測定をすることが可能となる。
【００７９】
したがって、測定対象物８の汚染レベルが例えば放射線検出手段１の検出限界付近であるなど、微小で統計精度が充分に得られない場合に、誤った分布補正となるのを防ぐことができる。そして、予め任意の統計精度となるような計数値を設定しておき、この値以下では分布情報が得られないという判断を行うことにより、統計精度が充分に得られない低いレベルの測定でも、誤った分布情報に基づいた結果を出力することを防止することが可能となる。
【００８０】
第７実施形態（図７）
図７は、本発明の第７実施形態を示す構成図である。
【００８１】
図７に示すように、本実施形態では、汚染面積算出手段９ｃと、表面汚染密度補正および算出手段１０ｃを備えている。
【００８２】
汚染面積算出手段９ｃは、計数結果から求めた放射線分布情報を使用して、放射線強度のプロファイルを求めるものである。すなわち、測定対象物８の移動方向の汚染の長さを求め、移動方向と直交する方向の長さ、例えば検出器の長さなど、予め決めた長さを使用して、汚染面積を算出する。
【００８３】
表面汚染密度補正および算出手段１０ｃは、放射能量換算手段４による計数結果から換算される放射能量を、求めた汚染面積で除算することにより、表面汚染密度を算出するものである。他の構成については前記実施形態とほぼ同様である。
【００８４】
本実施形態によれば、得られた放射線分布情報から汚染面積を算出する手段を設けているので、放射能量換算手段で得た総放射能量を測定した汚染面積で除算し表面汚染密度を求めることにより、実際の汚染面積を使用して表面汚染密度を求めるため正確な表面汚染密度を求めることが可能である。したがって、実際の汚染面積を用いて表面汚染密度を算出するため、過大な安全側評価とはならず、適正な評価結果を得ることが可能である。
【００８５】
第８実施形態（図８）
図８は、本発明の第８実施形態を示す構成図である。
【００８６】
図８に示すように、本実施形態では、放射線計数手段１からの値を逐次積算する逐次積算手段９ｄと、予め設定しておいた放射能量となるような計数値または計数率を閾値として記憶しておく閾値記憶手段１０ｄとを備えている。また、逐次積算された計数値または計数率と閾値を比較し、閾値以上となった場合に測定を終了させる、基準値判定および測定終了手段１１ａを備えている。他の構成については前記実施形態とほぼ同様である。
【００８７】
このような構成において、測定が開始されてから測定対象物８の全体の測定が終了するまでの間、放射線計数手段２の計測が終了した領域の計数値を逐次積算手段９によって逐次読み出され、読み出された値の積算が行われる。更に、基準値判定および測定終了手段１１ａにおいて、積算した計数値または計数率と、予め閾値設定手段１０ｄに設定記憶されている閾値とを比較し、設定した判定レベルの閾値を超えた場合、測定を終了させる。
【００８８】
本実施形態によれば、予め設定された放射能量に対応する計数率を閾値として記憶する手段と、放射線計数結果を逐次積算して前記閾値と比較する判定手段により、測定対象物全体の測定が終了する前に逐次積算した計数など測定結果が閾値を超えた時点で、測定を終了させるので、汚染レベルの高いものを測定したとき、短時間で汚染レベルの測定が可能である。
【００８９】
第９実施形態（図９）
図９は、本発明の第９実施形態を示す構成図である。
【００９０】
図９に示すように、本実施形態では、放射線計数手段２からの値を逐次積算する逐次計数積算手段３ａと、予め設定しておいた表面汚染密度を判定レベルとした閾値を記憶する閾値記憶手段１０ｄと、逐次放射能量に換算する放射能量換算手段４ａとを備えている。また、逐次汚染面積を算出する汚染面積算出手段９ｅと、逐次表面汚染密度に換算する表面密度算出手段１０ｅと、換算した表面汚染密度と閾値を比較して、閾値を超えた場合測定を終了させる基準値判定および測定終了手段１２とを備えている。他の構成については前記実施形態とほぼ同様である。
【００９１】
このような構成において、測定が開始されてから測定対象物８の全体の測定が終了するまでの間に、放射線計数手段２により計測が終了した領域の計数値を、逐次計数積算手段３ａにより、逐次読出しを行い積算する。更に放射能量換算手段４ａで逐次積算の終わったものから放射能量へ逐次換算する。
【００９２】
これと並行して、汚染面積算出手段９ｅにより、逐次積算の終わったものに対し、その時点で得られている放射線分布情報をもとに、その放射線強度のプロファイルを求める。これにより、測定対象物８の移動方向の汚染の長さを求め、移動方向と直交する方向の長さ、例えば検出器の長さなど前もって決めた長さを使用して、汚染面積を逐次算出する。
【００９３】
そして、表面汚染密度換算手段１０ｅにより、放射能量換算手段４ａで逐次換算された値を、汚染面積算出手段９ｅで逐次求めた面積で除算することにより、逐次表面汚染密度を算出する。
【００９４】
さらに、基準値判定および測定終了手段１２により、予め閾値記憶手段１１ｂに設定および記憶させておいた判定レベルと、表面汚染密度換算手段１０ｅにより逐次算出された値を、逐次比較し、閾値を超えた場合、測定を打ち切る。
【００９５】
本実施形態によれば、予め設定された表面汚染密度を閾値として記憶する手段と、放射線計数結果を逐次積算する手段と、更に逐次積算された結果から逐次放射線分布を求め、汚染面積を算出する手段と、逐次積算された結果から放射能量に換算し逐次算出された汚染面積で割り表面汚染密度を算出する手段と、逐次算出されてくる表面汚染密度と閾値を比較する判定手段により、測定対象物全体の測定が終了する前に逐次算出した表面汚染密度が閾値を越えた時点で測定を終了させるので、表面汚染密度の高いものを測定したとき、短時間で汚染レベルの判定が可能である。したがって、汚染の判定を早く行うことが可能であり、測定時間を短縮することができる。
【００９６】
第１０実施形態（図１０）
図１０は、本発明の第１０実施形態を示す構成図である。
【００９７】
図１０に示すように、本実施形態では、本実施形態は、往復で移動が可能な測定対象物往復搬送手段７ｂと、低速モード移行判定手段９ｆとを備えている。そして、例えば放射線検出手段１の検出下限レベルが高低の任意の２段階に設定され、往路では高いレベルでの測定が行われ、更に復路では往路より低いレベルでの測定が行われるようになっている。測定対象物往復搬送手段７ｂには、それぞれのレベルに対応した検出下限が得られる移動速度で、往路の速度は復路に比べ高速となるように設定される。また、往路の測定で汚染が検出された場合には、復路の測定は行う必要がなくなるため、最大速度で戻り移動が行われる。他の構成については前記実施形態とほぼ同様である。
【００９８】
このような構成において、まず往路の検出下限レベルより高い汚染レベルの測定対象物８を測定した場合について説明する。この場合には、往路の設定速度で測定対象物８が測定対象物往復搬送手段７ｂにより移動しながら測定が行われ、往路の測定が終了する。この時点で、検出下限レベル以上で汚染が計測されたため、低速モード移行判定手段９ｆにより、この値をもって測定完了とされる。すなわち、復路は測定しないと判定され、搬送速度および計測時間制御手段６ａにより、測定対象物往復搬送手段７ｂが高速に設定されて元の位置に戻る。
【００９９】
次に、往路の検出下限より低い汚染レベルの測定対象物を測定した場合について説明する。往路の測定が終了した時点では、測定結果が検出下限レベル以下となるため、汚染が検出されない。ここで低速モード移行判定手段９ｆにより、復路も測定と判定される。そして、搬送速度および計数時間制御手段６ａにより、更に低レベルの検出下限測定に対応した速度と計数時間間隔の設定がされる。次いで、往路よりも低速で復路の測定が行われる。復路の測定が終了した時点で、復路の検出下限レベル以上であれば汚染検出となり、この値をもって判定が行われる。なお、検出下限レベル以下であれば汚染無しと判定される。
【０１００】
また、別の例として、復路の速度設定を、往路と同一またはこれに近い速度とすることが可能である。この場合、往路の測定により汚染が検出下限レベル以下であると、復路での測定を行い、往路のデータを加算する。これにより、往路と復路を加算した時間分の測定データとなり、往路よりも低い検出下限レベルとすることもできる。
【０１０１】
本実施形態によれば、復路より往路が高い速度で移動できる測定対象物往復移動手段７ｂと、対象とする２種類の汚染レベルの検出下限値に対応した搬送速度および計数時間制御手段６ａと、往路の走査で検出下限値以下であった場合に復路の走査で更に低い汚染レベルに対応した移動速度に移行するための低速モード移行判定手段９ｆを備え、２段階の汚染レベル区分が可能となる。そして、往路の測定で検出下限以上の場合は、復路は最大速度で戻ることで測定時間の短縮が可能である。また、往路の測定で検出下限より低い場合は、更に低い速度で測定することができる。この場合には計数が増えるので、計数精度が向上し、精度良く汚染分布を測定することができる。したがって、往復測定で２段階の検出下限レベルを設定して測定することにより、比較的レベルの高いものと低いものを交えて測定する場合、レベル区分と測定時間の短縮が可能となる。
【０１０２】
【発明の効果】
以上で説明したように、本発明によれば、放射線検出手段の感度を低下させることなく、検出器の幅よりも詳細な分布を得ることができ、表面汚染密度に換算したときも精度良く求めることができる。
【図面の簡単な説明】
【図１】（Ａ）は本発明の第１実施形態による汚染検査装置を示す構成図、（Ｂ）は作用説明図。
【図２】本発明の第２実施形態による汚染検査装置を示す構成図。
【図３】本発明の第３実施形態による汚染検査装置を示す構成図。
【図４】本発明の第４実施形態による汚染検査装置を示す構成図。
【図５】本発明の第５実施形態による汚染検査装置を示す構成図。
【図６】本発明の第６実施形態による汚染検査装置を示す構成図。
【図７】本発明の第７実施形態による汚染検査装置を示す構成図。
【図８】本発明の第８実施形態による汚染検査装置を示す構成図。
【図９】本発明の第９実施形態による汚染検査装置を示す構成図。
【図１０】本発明の第１０実施形態による汚染検査装置を示す構成図。
【図１１】従来の汚染検査装置を示す構成図。
【符号の説明】
１ 放射線検出手段
２ 放射線計数手段
３ 計数積算手段
３ａ 逐次計数積算手段
４ 放射能量および汚染密度換算手段
４ａ 放射能量換算手段
５ 汚染分布表示手段
６ 搬送速度および計数時間制御手段
７ 測定対象物搬送手段
７ａ 検出器搬送手段
７ｂ 測定対象物往復搬送手段
８ 測定対象物
９ 積算計数比較手段
９ａ 任意積算手段
９ｂ 応答関数記憶手段
９ｃ 汚染面積算出手段
９ｄ 逐次積算手段
９ｇ 判定閾値記憶手段
１０ 選択計数記憶手段
１０ａ 応答関数分布補正手段
１０ｂ 分布精度判定手段
１０ｃ 表面汚染密度補正および算出手段
１０ｄ 閾値記憶手段
１０ｅ 表面汚染密度換算手段
１１ 分布補正手段
１１ａ 基準値判定および測定終了手段
１１ｂ 閾値記憶手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radioactive contamination inspection device, and more particularly to a radioactive contamination inspection device for improving radiation detection accuracy.
[0002]
[Prior art]
Generally, in a radioactive contamination inspection apparatus, means for performing scanning measurement by passing an object to be measured on the front surface of a detector is used, and a large article unloading monitor or the like is known as such an apparatus (for example, Patent Documents 1 and 2).
[0003]
In these apparatuses, generally, the distance corresponding to the width (direction of movement or scanning) of the detector is counted every time the object moves, and the contamination density is obtained from the sensitivity to the detector incident surface. Note that sensitivity calibration is generally performed by measuring a 10 cm × 10 cm area source.
[0004]
Such scanning measurement is used as a simple means for indicating the approximate position of contamination since contamination distribution information divided by the width of the detector is obtained. In addition, as one type of such scanning measurement, the entire measurement object is measured while repeating a cycle in which the measurement object moves by the width of the detector, stops, and performs measurement.
[0005]
FIG. 11 shows a configuration of a conventional contamination inspection apparatus. As shown in FIG. 11, the conventional contamination inspection apparatus includes a radiation detecting unit 1, a radiation counting unit 2 for counting the detected radiation, and a measuring object transport unit for loading and scanning the measuring object. The counting means 2 counts a signal from the radiation detecting means 1 every time the tray 7 moves a distance corresponding to the width of the detecting means 1 in the scanning direction.
[0006]
At the time of the contamination inspection, first, the measurement object 8 is placed on the tray 7, scanning is started from the tip of the tray, and counting is performed up to the position corresponding to the width of the detector. Next, counting is started again from this position, and counting is performed until the detector comes to the position of the tray 7 'and the measuring object 8'. Next, the position and the repetition data of the tray 7 ″ and the measurement target 8 ″ are acquired.
[0007]
As described above, after the measurement of the entire tray is completed, the radioactive contamination density of the object to be measured is obtained, and the measurement is completed.
[0008]
[Patent Document 1]
JP-A-11-212835
[0009]
[Patent Document 2]
JP-A-11-84012
[0010]
[Problems to be solved by the invention]
In the above-described conventional contamination inspection apparatus, the sensitivity is calibrated with a surface radiation source of 10 cm × 10 cm, and the calibration value is calculated based on a contamination distribution equivalent to 10 cm × 10 cm regardless of the actual contamination distribution. When the detector area is large and the contamination distribution is uniform, the contamination density Bq / cm2 is detected even if the Bq value of the total amount is the same as compared to the case where the contamination is unevenly distributed in 10 cm × 10 cm. It is evaluated as being excessive on the incident area of the vessel.
[0011]
In order to avoid such effects, it is necessary to measure the distribution of contamination in a smaller area, but in this case, the width of the detector must be reduced, and if the width is reduced, the detection sensitivity to contamination is reduced. There was a problem of getting worse.
[0012]
In addition, since the result of the contamination level is not obtained until one measurement is completed, even if the contamination level of the object to be measured is extremely large with respect to the judgment level, and the measurement can be performed in a short time, the sensitivity near the judgment level is sufficient. In order to obtain the measurement, it is necessary to perform measurement by setting the measurement time to an appropriate value, and the time to wait for the measurement to be completed becomes longer, so that there is a problem that the measurement time becomes longer.
[0013]
The present invention has been made in view of such circumstances, and it is possible to obtain a distribution that is more detailed than the width of the detector without lowering the sensitivity of the radiation detection means, and to obtain accuracy even when converted to surface contamination density. An object of the present invention is to provide a contamination inspection device that can be obtained well.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, in the invention according to claim 1, a radiation detecting means having a radiation detecting surface, a conveying means for moving an object to be measured along the radiation detecting surface of the radiation detecting means, Radiation counting means for counting and recording radiation at a length interval obtained by dividing the length of the radiation detection surface in the movement direction by an integer, and radiation corresponding to the length of the radiation detection surface in the movement direction. A counting and integrating means for integrating the counting, a radioactivity and a contamination density converting means for converting the integrated count into a radioactivity and a surface contamination density, and a contamination distribution displaying means for displaying the converted result and the distribution of radiation. Provided is a contamination inspection apparatus characterized in that:
[0015]
In the invention according to claim 2, there is provided transport means for moving the radiation detection surface of the radiation detection means along the measurement object in a state where the measurement object is stationary. A contamination inspection device as described above is provided.
[0016]
3. An integrated count comparing means for comparing data in a portion where measurement areas overlap with each other to select a larger one of count values, and a selected count storage means for storing count values of the selected areas. A contamination inspection apparatus according to claim 1 is provided.
[0017]
In the invention according to claim 4, an arbitrary width integrating means for integrating the counting of the radiation with a width shorter than the length of the radiation detecting surface in the moving direction of the measurement object, and a distribution of the counting of the radiation integrated to an arbitrary width are displayed. The contamination inspection apparatus according to claim 1, further comprising:
[0018]
In the invention according to claim 5, a radiation detecting means having a radiation detecting surface, a transporting means for moving an object to be measured along the radiation detecting surface of the radiation detecting means, and the radiation detection in a moving direction by the transporting means Radiation counting means for counting and recording radiation at a length interval obtained by dividing the length of the surface by an integer; and counting and accumulating means for integrating radiation counting so as to correspond to the length of the radiation detection surface in the moving direction. A response function storage means for storing a response function of the radiation detection means obtained in advance, and a response function distribution correction means for obtaining a radiation distribution by multiplying the measured count value by an inverse function of the response function. , A radioactivity and contamination density conversion means for converting the integrated counts into radioactivity and surface contamination density, and a contamination distribution table for displaying the conversion result and radiation distribution Providing contamination inspection apparatus characterized by comprising a means.
[0019]
In the invention according to claim 6, a determination threshold value storage unit that stores a count value having a preset statistical accuracy as a threshold value, a distribution accuracy determination unit that compares the count value obtained by radiation measurement with the threshold value, When the count value is lower than the threshold value, a uniform conversion process is performed without obtaining a radiation distribution, and when the count value is higher than the threshold value, a distribution correction unit that obtains a radiation distribution is provided. A contamination inspection device according to claim 1 or 5 is provided.
[0020]
In the invention according to claim 7, a contaminated area calculating means for obtaining the area of the contaminated distribution from the radiation distribution information obtained by the measurement, and the surface contaminated by calculating the total amount of the measured radioactivity by the obtained contaminated area. The contamination inspection apparatus according to claim 1 or 5, further comprising a surface contamination density correction and calculation means for converting the density into a density.
[0021]
In the invention according to claim 8, a threshold value storage means for storing a preset amount of radioactivity, a corresponding count value and a count rate as a threshold value, and a sequential integration for sequentially reading and integrating radiation count results at arbitrary intervals And means for comparing a result of successive integration with the threshold value, and a reference value determination and measurement termination means for terminating the measurement at the time when the sequentially counted radiation count result exceeds the threshold value. A contamination inspection device according to 1 or 5 is provided.
[0022]
According to the ninth aspect of the present invention, a threshold value storing means for storing a threshold value having a preset surface contamination density as a determination level, a sequential integrating means for sequentially reading and integrating radiation count results at arbitrary intervals, Sequential radioactivity conversion means for converting the integrated count to radioactivity, sequential contaminated area calculation means for calculating the contaminated area from the sequentially integrated count, and dividing the serially converted radioactivity by the sequentially calculated contaminated area. A surface contamination density conversion means for sequentially converting to the surface contamination density, and a reference value determination and measurement termination means for comparing the converted surface contamination density with the threshold value and terminating the measurement when the threshold value is exceeded. A contamination inspection apparatus according to claim 1 or 5, is provided.
[0023]
In the invention according to claim 10, the measuring object moving means capable of reciprocating movement, and the conveying speed and counting time controlling means capable of setting the measuring object moving means to an arbitrary different speed between the forward path and the backward path. And measuring the radiation at the set speed of the forward pass, performing a determination by low-speed measurement on the return pass when it is below the detection lower limit level, and performing a measurement on the return pass at a set speed lower than the forward pass. The contamination inspection apparatus according to claim 1 or 5, wherein:
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a contamination inspection device according to the present invention will be described with reference to FIGS.
[0025]
First Embodiment (FIGS. 1A and 1B)
FIG. 1A is a configuration diagram showing a first embodiment of the present invention, and FIG. 1B is an operation explanatory diagram.
[0026]
As shown in FIG. 1A, in the present embodiment, a radiation detecting means 1 using a detector typified by, for example, a plastic scintillation detector or a NaI (Tl) detector, and, for example, an amplifier and The apparatus includes a radiation counting means 2 including a counter and a computer for reading and storing a count value or a multi-channel scaler, a counting and integrating means 3, a radioactivity and contamination density converting means 4, and a contamination distribution displaying means 5. ing.
[0027]
The apparatus further includes a transport speed and counting time control unit 6 for setting and controlling the transport speed and the counting time interval of the measuring object, and a measuring object transporting unit 7. Then, the measuring object 8 is configured to move along the radiation detecting surface of the radiation detecting means 1 by the measuring object conveying means 7. The radiation detecting means 1 may have a structure in which one or more arbitrary number of detectors are arranged in a single layer or a multilayer structure in a direction perpendicular to the moving direction. Is not limited.
[0028]
In such a configuration, at the time of inspection, as shown in FIG. 1 (B), the measuring object 8 is moved by using the measuring object conveying means 7 set to a predetermined speed by the conveying speed and counting time control means 6. Radiation is detected by the radiation detecting means 1 while moving at an arbitrary speed. At this time, the conveying speed and counting time control means 6 controls the radiation counting means 2 to detect the radiation at the set speed at a time interval obtained by dividing the time required for the measuring object to move the distance of the detector width by an arbitrary integer. The radiation counting means 2 is controlled so that the radiation signal detected by the means 1 is counted.
[0029]
The radiation counting means 2 counts the signals detected by the radiation detecting means 1 based on the transport time and the measuring time set by the measuring time control means 6, and records the counted values in order. Then, the value counted by the radiation counting means 2 is read out by the counting and integrating means 3, and each count is sequentially integrated until the time when the measuring object moves by the distance of the detector width is reached. Distribution data corresponding to the number of divisions obtained by the corresponding moving distance is obtained.
[0030]
Next, the distribution data obtained by the counting and integrating means 3 is converted into the radioactivity and the surface contamination density of the measurement object by the radioactivity and contamination density conversion means 4, and the conversion result and the contamination are displayed by the contamination distribution display means 5. Display distribution information.
[0031]
Here, as an example, a case where the measurement object 6 having a length three times the width of the radiation detecting means 1 is counted by the radiation counting means 2 at a movement time interval of half the width of the radiation detecting means 1 is described. explain.
[0032]
First, the measurement is started in a state where the measurement object 8 is not yet positioned on the radiation detection means 1 and the tip of the measurement object 8 is at the end of the radiation detection surface of the radiation detection means 1.
[0033]
What is measured in the first counting time is a state in which the first area obtained by dividing the measuring object 8 into six equal parts is on the radiation detecting surface of the radiation detecting means 1, and is counted by the radiation counting means 2 at this time. The counted value is recorded as M1. What is measured in the second counting time is a state where the first area and the second area obtained by dividing the measuring object 8 into six equal parts are on the radiation detecting surface of the radiation detecting means 1. The count value counted by the counting means 2 is recorded as M2.
[0034]
What is measured in the third counting time is a state in which the second area and the third area obtained by dividing the measuring object 8 into six equal parts are on the radiation detecting surface of the radiation detecting means 1. The count value counted by the counting means 2 is recorded as M3. What is measured in the fourth counting time is a state in which the third area and the fourth area obtained by dividing the measuring object 8 into six equal parts are on the radiation detecting surface of the radiation detecting means 1. The count value counted by the counting means 2 is recorded as M4.
[0035]
What is measured in the fifth counting time is a state where the fourth area and the fifth area obtained by dividing the measuring object 8 into six equal parts are on the radiation detecting surface of the radiation detecting means 1. The count value counted by the counting means 2 is recorded as M5. What is measured in the sixth counting time is a state where the fifth region and the sixth region obtained by dividing the measurement object 8 into six equal parts are on the radiation detecting surface of the radiation detecting means 1. The count value counted by the counting means 2 is recorded as M6.
[0036]
What is measured in the seventh counting time is a state in which the sixth area obtained by dividing the measuring object 8 into six equal parts is on the radiation detecting surface of the radiation detecting means 1, and is counted by the radiation counting means 2 at this time. The counted value is recorded as M7.
[0037]
Next, the counting and integrating means 3 reads out the value counted and recorded by the radiation counting means 2 and integrates and records the count value corresponding to the moving time corresponding to the width of the radiation detecting means 1.
[0038]
In this case, the sum of the count values M1 and M2 corresponding to the first count time and the second count time is recorded as A1, and the count value M2 corresponding to the second count time and the third count time is recorded as A1. The value obtained by adding M3 is recorded as A2, and the value obtained by adding the count values M3 and M4 corresponding to the third count time and the fourth count time is recorded as A3.
[0039]
The sum of the count values M4 and M5 corresponding to the fourth count time and the fifth count time is recorded as A4, and the count values M5 and M6 corresponding to the fifth count time and the sixth count time are recorded. Is recorded as A5, and the sum of the count values M6 and M7 corresponding to the sixth count time and the seventh count time is recorded as A6.
[0040]
Next, the six distribution data from A1 to A6 obtained by the counting and integrating means 3 are converted into respective quantitative values by the radioactivity and contamination density conversion means 4, and the conversion result is further displayed by the contamination distribution display means. Is displayed, and the measurement is terminated.
[0041]
According to this embodiment, the measurement target is moved along the radiation detection surface of the radiation detection means, and measurement is performed at arbitrary time intervals such that the movement distance is shorter than the width (distance in the movement direction) of the radiation detection surface. However, the counting does not decrease by integrating the movement time for the detector width. Therefore, the measurement can be performed in a finer pattern without reducing the sensitivity by reducing the width of the detector, and the radiation distribution can be accurately measured.
[0042]
Therefore, it is possible to obtain a count in the same measurement time as counting by the width of the radiation detection means, and it is possible to obtain twice as many radiation distribution information in the moving direction.
[0043]
Second embodiment (FIG. 2)
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
[0044]
The present embodiment has a configuration in which a radiation detector moving unit 7a is provided in place of the measuring object transporting unit 7 of the first embodiment.
[0045]
That is, as shown in FIG. 2, in the present embodiment, in a state where the measurement object 8 is stationary, the radiation detector moving means 7a moves the radiation detection means 1 along the measurement object 1 while the radiation detection surface Is measured at arbitrary time intervals such that the movement distance is shorter than the width (distance in the movement direction). In addition, for a fixed object such as a wall surface or a large and difficult-to-move object 8 to be measured, the width of the radiation detecting means 1 can be narrowed so that the radiation distribution can be accurately measured without lowering the sensitivity. It is.
[0046]
According to the present embodiment, a radiation count similar to that of the first embodiment is obtained, and even if the measurement target 8 is a large device or a building such as a wall that is difficult to be transported by the device, The same detailed radiation distribution information as in the first embodiment can be obtained.
[0047]
Third embodiment (FIG. 3)
FIG. 3 is a configuration diagram showing a third embodiment of the present invention.
[0048]
As shown in FIG. 3, in the present embodiment, as a means for easily correcting the radiation distribution information in the moving direction with respect to the distribution data integrated by the counting and integrating means 3, the output of the counting and integrating means 3 is integrated and counted. The configuration is such that comparison means 9 and selection count storage means 10 are provided. Other configurations are substantially the same as those of the above-described embodiment.
[0049]
In such a configuration, at the time of inspection, the positions of the outputs A1 and A2 of the counting and integrating means 3 overlap each other by a half of the detector width. In this case, if it is to be expressed as a one-dimensional distribution, data processing of the overlapping portion is required. Therefore, as a means for easily performing processing without performing complicated calculations and calibration, areas of overlapping portions are compared, and a larger value is selected and adopted for this area.
[0050]
In the following order, the outputs of A1 to A6 of the counting and integrating means 3 are compared by the counting and comparing means 9 to determine the overlapping area. The area where A1 does not overlap is selected as the value of A1, and is stored as the value of this area by the selection count storage means 10.
[0051]
A1 and A2 overlap each other at half the detector width. By comparing these A1 and A2, the larger one is selected as the value of the overlapped area, and the selected count storage means 10 stores it as the value of this area.
[0052]
A2 and A3 overlap each other at half the detector width. By comparing A2 and A3, the larger one is selected as the value of the overlapped area, and the selected count storage means 10 stores it as the value of this area. The positions of A3 and A4 overlap each other by a half of the detector width. By comparing A3 and A4, the larger one is selected as the value of the overlapped area, and the selected count storage means 10 stores it as the value of this area.
[0053]
A4 and A5 overlap each other at half the detector width. By comparing A4 and A5, the larger one is selected as the value of the overlapped area, and the selected count storage means 10 stores it as the value of this area.
[0054]
A5 and A6 overlap each other at half the detector width. By comparing A5 and A6, the larger one is selected as the value of the overlapped area, and the selected count storage means 10 stores it as the value of this area. The area where A6 does not overlap is selected as the value of A6, and the selected count storage means 10 stores it as the value of this area.
[0055]
In such a configuration, at the time of inspection, distribution information as a result of processing overlapping areas is obtained from the value of each area stored in the selection counting storage means.
[0056]
According to the present embodiment, when the distribution of radiation is obtained from the integration result of the count for the width of the radiation detection surface, data processing is necessary because there is an area where the measurement areas overlap, but the integration results where the measurement areas overlap each other are required. Is provided, and a means for selecting a larger value as a value of the area is provided, so that data processing is performed with a simple configuration, and since a larger value is always selected, it can be evaluated on the safe side. It is possible.
[0057]
Therefore, it is possible to easily correct the value of the counting and integrating means 3 and obtain it as radiation distribution information, and since a large value is selected, there is also obtained an effect that an index giving importance to safety is provided.
[0058]
Fourth embodiment (FIG. 4)
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.
[0059]
As shown in FIG. 4, in the present embodiment, apart from the means for integrating the count value corresponding to the movement time for the width of the detector, the count value corresponding to an arbitrary movement time shorter than the width of the detector is calculated. An arbitrary width integrating means 9 for performing integration is provided. Other configurations are substantially the same as those of the above-described embodiment.
[0060]
That is, in the above-described embodiment, as the value to be input to the radioactivity and contamination density converting means 4, the value obtained by the counting and integrating means 3 for integrating the count value corresponding to the moving time corresponding to the width of the radiation detecting means 1 is used. However, in the present embodiment, in order to obtain more accurate distribution information, the arbitrary width integrating means 9a which integrates a count value corresponding to an arbitrary moving time shorter than the width of the detector, obtains a finer value, and obtains contamination. The distribution is displayed.
[0061]
In such a configuration, at the time of inspection, if the moving time set by the arbitrary width integrating means 9a for integrating a count value corresponding to an arbitrary moving time is the same as the time interval counted by the radiation counting means 2, radiation The count M1 output from the counting means 2 is recorded as B1 in the arbitrary width integrating means 9a. The count M2 output from the radiation counting means 2 is recorded in the arbitrary width integrating means 9a as B2, and the count M3 output from the radiation counting means 2 is recorded in the arbitrary width integrating means 9a as B3.
[0062]
The count M4 output from the radiation counting means 2 is recorded as B4 in the arbitrary width integrating means 9a, and the count M5 output from the radiation counting means 2 is recorded as B5 in the arbitrary width integrating means 9a. The count M6, which is the output of the radiation counting means 2, is recorded as B6 in the arbitrary width integrating means 9a. The count M7 output from the radiation counting means 2 is not used because it is not integrated.
[0063]
According to this embodiment, by providing a means for integrating the radiation counting result at an arbitrary time between the counting time interval of the radiation counting means and the movement time interval of the width of the radiation detection surface, the width of the radiation detection surface The center position of the distribution can be obtained in more detail than the distribution information obtained by the integration of minutes, and the contamination distribution can be measured with high accuracy.
[0064]
Therefore, it is possible to obtain a more detailed distribution center than when using a value integrated by the detector width.
[0065]
Fifth embodiment (FIG. 5)
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.
[0066]
As shown in FIG. 5, in the present embodiment, in order to obtain more accurate distribution information, a response function storage unit 9b that stores a response function of the radiation detection unit 1 that has been obtained in advance, and a response function that responds to the measured count value. A response function distribution correction means 10a for obtaining a radiation distribution by multiplying a function is added. Other configurations are substantially the same as those of the above-described embodiment.
[0067]
That is, a response function, which is the radiation detection efficiency standardized for each measurement position, corresponding to the size and number of detectors and the dimensions of a plurality of types of measurement targets 8 is obtained from the radiation detection means 1. Is stored in the response function storage means 9b. Then, accurate radiation distribution information is obtained by multiplying the count value at each measurement position obtained as a result of the measurement of the measurement object 8 by the inverse function of the corresponding response function by the response function distribution correction means 10a.
[0068]
In the example described above, the distribution of contamination is at six positions D1 to D6, and the detector is twice the length of the region. On the other hand, it is assumed that seven measurement data of M1 to M7 are measured. The counts obtained for unknown radiation distributions for each location of contamination are given by the following relationships:
[0069]
(Equation 1)

Here, R11 to R76 are response functions of the radiation detecting means 1, D1 to D6 are radiation distributions, and M1 to M7 are counting results obtained by the radiation counting means 2.
[0070]
According to the above equation, the values of the contamination distributions D1 to D6 are obtained by multiplying the values of the counting results M1 to M7 by the inverse functions of the response functions R11 to R76.
[0071]
For example, when the response of the detector when the position of the radiation distribution to be obtained is in front of the detector is 1, and the response of the detector when the position is not the front is 0, the following response function is obtained.
[0072]
(Equation 2)

Note that M1 to M7 may be A1 to A6 obtained from the count integration result.
[0073]
According to the present embodiment, since the radiation distribution information is obtained by multiplying the measured data by the inverse function of the response function of the radiation detection sensitivity to the radiation detection means that has been obtained in advance, it is possible to obtain a distribution finer than the size of the detector. It is possible to accurately measure the distribution of contamination.
[0074]
Sixth embodiment (FIG. 6)
FIG. 6 is a configuration diagram showing a sixth embodiment of the present invention.
[0075]
As shown in FIG. 6, the present embodiment includes a judgment threshold value storage unit 9g that stores a count value having an arbitrary statistical accuracy as a threshold value. The apparatus further includes a distribution accuracy determination unit 10b that compares the count value input from the count integration unit 3 with a threshold value and determines that distribution correction is not performed if the count value is equal to or smaller than the threshold value. In addition, a distribution correction unit 11 is provided for performing processing when distribution correction is not performed as a result of the determination, and performing processing for obtaining and correcting radiation distribution when determining to perform distribution correction. Other configurations are substantially the same as those of the above-described embodiment.
[0076]
In such a configuration, at the time of inspection, the count values obtained by the radiation detecting means 1, the radiation counting means 2, and the counting and accumulating means 3 are stored in the determination threshold storage means 9g in advance by the distribution accuracy determination means 10b. Is compared to If the count value is lower than the threshold value, distribution accuracy cannot be obtained, and it is determined that distribution correction is not performed. When the count value is higher than the threshold value, it is determined that the radiation distribution is obtained and corrected in order to increase the distribution accuracy.
[0077]
If it is determined that distribution correction is not to be performed, the distribution correction means 11 uniformly performs a conversion process evaluated on the safe side, such as dividing the amount of radioactivity by a predetermined area to calculate the surface contamination density. Done. Further, the correction may be performed on the assumption that the contamination is uniform. If it is determined that distribution correction is to be performed, the distribution correction means 11 performs distribution processing by obtaining distribution information from the obtained count.
[0078]
In this embodiment, as described above, the count value serving as a preset statistical error is stored as a threshold, and the radiation count value is compared with the threshold. A uniform conversion process is performed, and if it is equal to or larger than the threshold value, the radiation distribution is obtained from the measurement result. As a result, even when the radiation count value is small and sufficient statistical accuracy cannot be obtained, it is possible to perform sufficiently reliable measurement.
[0079]
Therefore, when the contamination level of the measurement object 8 is small and the statistical accuracy is not sufficiently obtained, for example, when the detection level is near the detection limit of the radiation detecting means 1, it is possible to prevent incorrect distribution correction. Then, a count value is set in advance so as to have an arbitrary statistical accuracy, and by determining that distribution information cannot be obtained below this value, even at a low-level measurement where the statistical accuracy is not sufficiently obtained, It is possible to prevent output of a result based on incorrect distribution information.
[0080]
Seventh embodiment (FIG. 7)
FIG. 7 is a configuration diagram showing a seventh embodiment of the present invention.
[0081]
As shown in FIG. 7, the present embodiment includes a contaminated area calculation unit 9c and a surface contamination density correction and calculation unit 10c.
[0082]
The contaminated area calculating means 9c obtains a radiation intensity profile using the radiation distribution information obtained from the counting result. That is, the length of contamination in the moving direction of the measurement target 8 is obtained, and the contamination area is calculated using a predetermined length such as a length in a direction orthogonal to the moving direction, for example, a detector length. .
[0083]
The surface contamination density correction and calculation unit 10c calculates the surface contamination density by dividing the radioactivity converted from the counting result by the radioactivity conversion unit 4 by the obtained contaminated area. Other configurations are substantially the same as those of the above-described embodiment.
[0084]
According to the present embodiment, since the means for calculating the contaminated area from the obtained radiation distribution information is provided, the surface contamination density is obtained by dividing the total radioactivity obtained by the radioactivity conversion means by the measured contaminated area. Accordingly, it is possible to obtain an accurate surface contamination density because the surface contamination density is obtained using the actual contaminated area. Therefore, since the surface contamination density is calculated using the actual contaminated area, it is possible to obtain an appropriate evaluation result without excessive safety evaluation.
[0085]
Eighth embodiment (FIG. 8)
FIG. 8 is a configuration diagram showing an eighth embodiment of the present invention.
[0086]
As shown in FIG. 8, in the present embodiment, a sequential integrating means 9d for sequentially integrating the values from the radiation counting means 1 and a count value or a counting rate which becomes a preset radioactivity amount is stored as a threshold value. And a threshold storage unit 10d to be stored. Further, a reference value judging and measurement ending means 11a is provided for comparing the counted value or the counting rate successively integrated with the threshold value, and terminating the measurement when the counted value or the count value exceeds the threshold value. Other configurations are substantially the same as those of the above-described embodiment.
[0087]
In such a configuration, from the start of the measurement to the end of the entire measurement of the measurement object 8, the count value of the area where the measurement of the radiation counting unit 2 has been completed is sequentially read out by the sequential integrating unit 9. , The read values are integrated. Further, the reference value determination and measurement end means 11a compares the integrated count value or count rate with a threshold value previously set and stored in the threshold value setting means 10d. To end.
[0088]
According to the present embodiment, the measurement of the entire measurement object is performed by means for storing a count rate corresponding to a preset amount of radioactivity as a threshold value and determination means for sequentially integrating radiation count results and comparing the result with the threshold value. Since the measurement is terminated when the measurement result, such as a count that is successively integrated before the termination, exceeds the threshold value, the measurement of the contamination level can be performed in a short time when a high contamination level is measured.
[0089]
Ninth embodiment (FIG. 9)
FIG. 9 is a configuration diagram showing a ninth embodiment of the present invention.
[0090]
As shown in FIG. 9, in the present embodiment, a sequential counting and integrating means 3a for sequentially integrating the values from the radiation counting means 2 and a threshold storage for storing a threshold with a preset surface contamination density as a determination level. There is provided a means 10d and a radioactivity conversion means 4a for sequentially converting to radioactivity. In addition, the contaminated area calculating means 9e for sequentially calculating the contaminated area, the surface density calculating means 10e for sequentially converting to the surface contaminated density, and comparing the converted surface contaminated density with the threshold value, terminate the measurement if the threshold value is exceeded. Reference value determination and measurement end means 12 is provided. Other configurations are substantially the same as those of the above-described embodiment.
[0091]
In such a configuration, from the start of the measurement to the end of the entire measurement of the measurement object 8, the count value of the area where the measurement has been completed by the radiation counting unit 2 is sequentially counted and accumulated by the counting and integrating unit 3 a. Perform sequential reading and integration. Further, the radioactivity conversion means 4a sequentially converts the ones for which the sequential integration has been completed into radioactivity.
[0092]
In parallel with this, a profile of the radiation intensity is obtained by the contaminated area calculating means 9e on the basis of the radiation distribution information obtained at the time of the successive integration. Thereby, the length of the contamination in the moving direction of the measuring object 8 is obtained, and the contaminated area is sequentially calculated using the length orthogonal to the moving direction, for example, the length of the detector, etc. I do.
[0093]
Then, the surface contamination density is calculated sequentially by dividing the value sequentially converted by the radioactivity conversion means 4a by the surface contamination density conversion means 10e by the area sequentially calculated by the contamination area calculation means 9e.
[0094]
Further, the reference level determination and measurement termination unit 12 sequentially compares the determination level previously set and stored in the threshold storage unit 11b with the value sequentially calculated by the surface contamination density conversion unit 10e, and exceeds the threshold. If so, abort the measurement.
[0095]
According to the present embodiment, a means for storing a preset surface contamination density as a threshold, a means for sequentially integrating radiation count results, and further obtaining a sequential radiation distribution from the sequentially integrated results to calculate a contaminated area. Means for measuring the surface contamination density by dividing the sequentially integrated result into radioactivity and dividing by the sequentially calculated contamination area; and determining means for comparing the sequentially calculated surface contamination density with a threshold value. Since the measurement is terminated when the sequentially calculated surface contamination density exceeds the threshold value before the measurement of the entire object is completed, it is possible to determine the contamination level in a short time when measuring a material having a high surface contamination density. . Therefore, the determination of contamination can be made quickly, and the measurement time can be shortened.
[0096]
Tenth embodiment (FIG. 10)
FIG. 10 is a configuration diagram showing a tenth embodiment of the present invention.
[0097]
As shown in FIG. 10, in the present embodiment, the present embodiment is provided with a reciprocating transporting means 7b of the measuring object which can move reciprocally, and a low-speed mode shift determining means 9f. Then, for example, the detection lower limit level of the radiation detecting means 1 is set to any two levels of high and low, and a measurement at a high level is performed on the outward path, and a measurement at a lower level than the outward path is performed on the return path. I have. The reciprocating conveyance means 7b is set so that the forward speed is higher than the return speed at a moving speed at which a detection lower limit corresponding to each level is obtained. Further, when contamination is detected in the measurement of the forward path, the return movement is performed at the maximum speed since the measurement of the return path does not need to be performed. Other configurations are substantially the same as those of the above-described embodiment.
[0098]
In such a configuration, first, a case will be described in which the measurement target 8 having a contamination level higher than the detection lower limit level of the outward path is measured. In this case, the measurement is performed while the measurement object 8 is being moved by the measurement object reciprocating transport means 7b at the set speed of the outward path, and the measurement of the outward path is completed. At this point, since the contamination was measured at the detection lower limit level or more, the measurement is completed by the low speed mode transition determination means 9f with this value. That is, it is determined that the return path is not measured, and the reciprocating transporting means 7b of the measuring object is set to a high speed by the transport speed and measuring time control means 6a, and returns to the original position.
[0099]
Next, a case where a measurement target having a contamination level lower than the detection lower limit of the outward path is measured will be described. At the time point when the measurement on the outward path is completed, the measurement result is equal to or lower than the detection lower limit level, so that no contamination is detected. Here, the returning path is also determined to be measured by the low-speed mode shift determining means 9f. Then, the conveying speed and counting time control means 6a sets a speed and a counting time interval corresponding to the lower-level detection lower limit measurement. Next, the measurement of the return path is performed at a lower speed than the outward path. At the time when the measurement of the return path is completed, if the return path is equal to or higher than the detection lower limit level, contamination detection is performed, and the determination is performed using this value. In addition, if it is below the detection lower limit level, it is determined that there is no contamination.
[0100]
As another example, it is possible to set the speed of the return trip to be the same as or close to the forward trip. In this case, if the contamination is less than the detection lower limit level by the measurement of the forward path, the measurement of the return path is performed, and the data of the forward path is added. As a result, the measurement data for the time obtained by adding the forward path and the return path is obtained, and it is possible to set the detection lower limit level lower than that of the forward path.
[0101]
According to the present embodiment, the measurement object reciprocating means 7b capable of moving at a higher speed on the outward path than on the return path, the transport speed and counting time control means 6a corresponding to the detection lower limit values of the two types of target contamination levels, A low-speed mode shift determination unit 9f is provided for shifting to a moving speed corresponding to a lower contamination level in the return scan when the detection is less than the lower limit of detection in the forward scan. . When the measurement of the forward path is equal to or larger than the lower limit of detection, the return path returns at the maximum speed, so that the measurement time can be reduced. Further, when the measurement in the outward path is lower than the lower detection limit, the measurement can be performed at a lower speed. In this case, the counting is increased, so that the counting accuracy is improved and the contamination distribution can be accurately measured. Therefore, by setting the detection lower limit level in two steps in the reciprocating measurement and performing the measurement with a relatively high level and a low level, it is possible to shorten the level division and the measurement time.
[0102]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a more detailed distribution than the width of the detector without lowering the sensitivity of the radiation detection unit, and to obtain the distribution accurately when converted to the surface contamination density. be able to.
[Brief description of the drawings]
FIG. 1A is a configuration diagram showing a contamination inspection apparatus according to a first embodiment of the present invention, and FIG.
FIG. 2 is a configuration diagram showing a contamination inspection device according to a second embodiment of the present invention.
FIG. 3 is a configuration diagram showing a contamination inspection device according to a third embodiment of the present invention.
FIG. 4 is a configuration diagram showing a contamination inspection device according to a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram showing a contamination inspection device according to a fifth embodiment of the present invention.
FIG. 6 is a configuration diagram showing a contamination inspection device according to a sixth embodiment of the present invention.
FIG. 7 is a configuration diagram showing a contamination inspection device according to a seventh embodiment of the present invention.
FIG. 8 is a configuration diagram showing a contamination inspection device according to an eighth embodiment of the present invention.
FIG. 9 is a configuration diagram showing a contamination inspection device according to a ninth embodiment of the present invention.
FIG. 10 is a configuration diagram showing a contamination inspection device according to a tenth embodiment of the present invention.
FIG. 11 is a configuration diagram showing a conventional contamination inspection device.
[Explanation of symbols]
1 Radiation detection means
2 Radiation counting means
3 Counting and integrating means
3a Sequential counting and integrating means
4 Radioactivity and contamination density conversion means
4a Radioactivity conversion means
5 Contamination distribution display means
6 Transport speed and counting time control means
7 Measured object transport means
7a Detector transport means
7b Reciprocating conveyance means for the object to be measured
8 Measurement object
9 Integrated counting comparison means
9a Optional integration means
9b Response function storage means
9c Contaminated area calculation means
9d successive integration means
9g judgment threshold storage means
10 Selection counting storage means
10a Response function distribution correction means
10b Distribution accuracy determination means
10c Surface contamination density correction and calculation means
10d threshold storage means
10e Surface contamination density conversion means
11 Distribution correction means
11a Reference value judgment and measurement end means
11b threshold storage means

Claims (10)

Radiation detecting means having a radiation detecting surface, conveying means for moving an object to be measured along the radiation detecting surface of the radiation detecting means, and dividing the length of the radiation detecting surface in the moving direction by the conveying means by an integer Radiation counting means for counting and recording radiation at the set length interval, counting integration means for integrating the radiation count corresponding to the length of the radiation detection surface in the moving direction, and radioactivity A contamination inspection apparatus, comprising: a radioactivity amount and a contamination density conversion means for converting into a surface contamination density; and a contamination distribution display means for displaying a result of the conversion and a distribution of radiation. The contamination inspection apparatus according to claim 1, further comprising a transport unit that moves the radiation detection surface of the radiation detection unit along the measurement object while the measurement object is stationary. The apparatus according to claim 1, further comprising: integrated count comparing means for comparing data in a portion where the measurement areas overlap with each other to select a larger count value; and selective count storage means for storing a count value of the selected area. The contamination inspection device according to 1. Arbitrary width integrating means for integrating the radiation count in a width shorter than the length of the radiation detection surface in the moving direction of the measurement object, and means for displaying a radiation count distribution integrated in an arbitrary width. The contamination inspection device according to claim 1, wherein Radiation detecting means having a radiation detecting surface, conveying means for moving an object to be measured along the radiation detecting surface of the radiation detecting means, and dividing the length of the radiation detecting surface in the moving direction by the conveying means by an integer Radiation counting means for counting and recording radiation at the set length interval, and counting integration means for integrating radiation counting to correspond to the length of the radiation detection surface in the movement direction, Response function storage means for storing a response function of the radiation detection means, response function distribution correction means for obtaining a radiation distribution by multiplying the measured count value by an inverse function of the response function, and a radioactivity amount and It is characterized by comprising radioactivity and contamination density conversion means for converting to surface contamination density, and contamination distribution display means for displaying the result of the conversion and the distribution of radiation. To pollution inspection apparatus. A determination threshold value storage unit that stores a count value having a predetermined statistical accuracy as a threshold value, a distribution accuracy determination unit that compares the count value obtained by radiation measurement with the threshold value, and the count value is lower than the threshold value. 6. The contamination according to claim 1, further comprising: a distribution correction unit that performs a uniform conversion process without obtaining a radiation distribution in a case, and obtains a radiation distribution when the count value is higher than the threshold value. Inspection equipment. Contamination area calculation means for calculating the area of contamination distribution from radiation distribution information obtained by measurement, and surface contamination density correction for converting the total amount of measured radioactivity to the surface contamination density by decrementing by the obtained contamination area The contamination inspection apparatus according to claim 1, further comprising: a calculation unit. A predetermined amount of radioactivity, a threshold storage means for storing a count value and a count rate corresponding thereto as a threshold, a sequential integration means for sequentially reading and integrating radiation count results at arbitrary intervals, and a result of the sequential integration The contamination inspection apparatus according to claim 1, further comprising a reference value determination and measurement termination unit configured to compare the threshold value and terminate the measurement when the sequentially counted radiation count result exceeds the threshold value. . Threshold storage means for storing a threshold with a predetermined surface contamination density as a determination level; sequential integration means for sequentially reading and integrating radiation count results at arbitrary intervals; and sequentially integrating the counts into radioactivity A sequential radioactivity conversion means for converting, a contaminated area calculation means for calculating the contaminated area from the sequentially integrated count, and a surface contaminated density by dividing the sequentially converted radioactivity by the sequentially calculated contaminated area 2. The method according to claim 1, further comprising: means for sequentially converting the surface contamination density; and a reference value judging / measurement ending means for comparing the converted surface contamination density with the threshold value and terminating the measurement when the threshold value is exceeded. Or the contamination inspection device according to 5. A measuring object moving means capable of reciprocating movement, a conveying speed and a counting time controlling means capable of being set to an arbitrary speed different between the forward movement and the returning movement with respect to the measuring object moving means, and a setting speed of the forward movement. Means for performing determination by low-speed measurement on the return path when the measured radiation is less than the detection lower limit level, and performing measurement on the return path at a set speed lower than the forward path. Item 6. The contamination inspection device according to item 1 or 5.

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